Bill Gates

Microsoft founder Bill Gates has retained the title of the richest man in the U.S. for a 17th year. He topped a Forbes list of America's 400 richest people again this year with a fortune of US$54 billion, up from $50 billion in 2009.

A total of 217 people on the list saw their wealth grow this year, in contrast to last year when 314 saw their fortunes decline, the U.S. business magazine reported.

Investor Warren Buffett came in second with $45 billion, followed by Oracle founder and CEO Lawrence Ellison ($27 billion) and Christy Walton ($24 billion), widow of John Walton, the Wal-Mart heir who died in a plane crash in 2005.

Mexican telecom tycoon Carlos Slim Helú remained on top of Forbes' list of the world's richest people with assets worth US$60 billion.